KB 949260 - An interesting OCS 2007 update has shown up - related to communicating with LCS 2005 and requires client updates

Check out this update - KB 949260 - here.

Normally I’d write this off as a one-off or an isolated issue, but what caught my interest was the fact that it appears as a High-Priority Update to be installed on all your OCS servers in your organization.

And here is the other oddity that doesn’t seem to be documented very well – which basically requires a LOT of client updates, and makes it sound like someone figured out how to spoof OCS/LCS packets:

This update package replaces the OCS2007-KB946763-x86-Server.msp update package KB 946763 - Update package for Communications Server 2007 (Web Components, Admin Tools, Web Conferencing, Audio Video, Mediation, Archiving, and Server): January 31, 2008

Note: The authentication protocol that is used by Communications Server and its clients has been updated to require a signature in all messages. This includes the first message that carries the challenge response. The version number of the protocol that is advertised in the challenge response has increased to version 4. Challenge responses that use version 4 of the protocol must contain a signature. The signature is a digest of the identifying headers in the message that is calculated by using the session key. To make the Conferencing Add-in for Microsoft Office Outlook work correctly, this update for the Conferencing Add-in must be installed.

Additionally, to make sure that all other clients work effectively against this update, the following hotfixes must be installed on the clients:

KB 948738 - Update for the Conferencing Add-in for Outlook: April 11, 2008

KB 946764 - Windows-based Live Meeting 2007 client update package: April 11, 2008

KB 946164 - Update for Communicator 2007: April 2, 2008